For those of you who have rooted your newly updated OTA 2.2, setCPU seems to be working.
I was able to set profiles and underclock the phone.
The only clock speeds available are 300MHz, 600MHz, 800MHz and 1000MHz.
Governors available are ondemand, userspace and performance.
I slowed it down to max speed of 300MHz and it does appear to have an effect...though not dramatic.
Just some FYI in case you'd like to try it out and see if this would help battery life, especially while the screen is off.
As a precaution, this should be attempted at your own risk as I don't know how it will affect your phone.